Man buried alive after tunnel collapses near Vatican.

A police investigation is underway in Rome after a man became trapped in a tunnel about six metres under a street near the Vatican on Thursday morning.

Firefighters worked throughout the day to rescue the man, allegedly part of a criminal gang, extracting him from the rubble after a complex eight-hour operation.

His four accomplices managed to free themselves from the collapsed tunnel but were stopped by police as they fled the scene. All had criminal records, including for robbery, according to Italian news reports.

It is believed that the gang was preparing to carry out a heist at a nearby bank, taking advantage of Italy's Ferragosto public holiday with the capital semi-deserted this weekend.

The dramatic incident occurred after part of the asphalt gave way on Via Innocenzo XI, off the busy Via Gregorio VII, just up the street from St Peter's.

After a member of the gang alerted emergency services of the collapse, firefighters and police detected a voice from beneath the rubble, about six metres down, in front of a vacant shop.

Rescuers dug a parallel hole to reach the man, who was critically injured, providing him with oxygen and liquids.

After eight hours they managed to extract the would-be robber alive, to applause from the large crowd of bystanders.

Police are working on the theory that the gang was preparing to use the tunnel, which started inside the empty shop, to reach the vault of one of two nearby banks.

Two of the gang members, from Naples, were arrested for resisting a public official and two others, from Rome, were cited for damage to public property, according to state broadcaster Rai News.

Cover photo Vigili del Fuoco